The present invention relates to an arrangement for mounting an object to a support structure having a rear side which is difficult of access, such as having hollow cavities at the rear side.
In general, the prior art has encountered very serious difficulties when it is desired to mount an object on a wall or support structure having hollow cavities at the rear side thereof. It has been proposed to utilize a dovel whose anchoring element passes through a mounting hole into a cavity or the like at the rear side of the support structure and is anchored therein by means of tilting or spreading. Such a dovel possesses a disadvantage that it is expensive, requires provision of a relatively big mounting hole, and is frequently complicated and difficult to handle.
A mounting element for mounting an object to a hollow wall or the like has further been proposed, which has an inner thread and several finger-like spreading legs. The latter are radially urged toward one another when the mounting element is inserted into the mounting hole by means of a mounting screw. When the finger-like legs passes into a hollow cavity, they substantially spread apart from one another. Under the pulling action of the mounting screw these spreading legs are gradually brought in contact with the rear side of the wall, for instance with considerable deformation. This results from the fact that the spreading legs approach and abut the rear side of the wall substantially parallel to the latter. Occasionally, these spreading legs can partially or completely penetrate into the wall at the rear side. Such a mounting element is disadvantageous because of uncontrollable behavior of its spreading legs and excessive elasticity of the latter. Furthermore, it must be provided with a long thread whereby a considerable mounting time is required.
A further disadvantage of the abovementioned known mounting element results from the fact that it behaves differently in the support structures or walls which are constituted by soft or hard materials. When the mounting element is used for the support structures which are constituted by soft materials, resistance of the support structure which is required for spreading of the mounting element and particularly hardness and stability of the support structure can be not sufficient so that the spreading legs of the mounting element penetrate into the support structure or wall. In such a case there is a danger that an edge of the mounting hole of the support structure will be damaged. Furthermore, in such a construction practically no definite mounting conditions are attained inasmuch as an optimum mounting position, similar to the construction with substantially flat abutment of the spreading legs, is at least difficult or completely impossible to be distinguished during screwing of the mounting screw.
The fore-mentioned mounting element also possesses a disadvantage that required centering of the same in the mounting hole is impossible, or possible only with the aid of additional means, such as special screws and the like.